This Center Grant research and research training program is concerned with the effects of physical and chemical factors in the environment on biologic systems, with particular emphasis on the health of man. Biologic effects include impairment of function, as well as initiation or aggravation of illness, disability and premature death. Although no disease is excluded from consideration, primary interest focuses on cancer, chronic lung disease of specific or nonspecific etiology, heart disease, and birth defects. The general approaches employed in these studies are toxicologic and epidemiologic. Toxicologic approaches include a wide variety of biochemical and physiologic methods applied to biologic systems ranging from cells to whole organisms. Epidemiologic methods also cover a wide range, from field studies to analyses of vital records and case-control studies. Environmental factors under study include (a) occupational hazards, with specific interest in carcinogens, pulmonary pathogenic substances, neurotoxic and cardiotoxic compounds, (b) community air pollution, (c) cigarette smoking (which complicates all studies of chronic disease), (d) radiation, with particular interest in mechanisms of pulmonary carcinogenesis and general cellular effects, including DNA injury and repair, and malignant transformation, and (e) pesticides, plastics and other chemicals of concern in industry or the general environment.